Standard was 4 on demountable rims. 5 on wire rims. 6 on aftermarket or accessory type wheels I believe. Might be wrong, but don't see them in '26 parts book.
That was a conversion done so you could change the wheel if you had a flat. Murray Fahnestock's book "The Model T Ford Owner" shows how to do it. Of course, it you have two different size wheels you have to carry two spare wheels with the tires mounted.
Tom,
A clarification is needed. Were the 6 lug nuts you refer to on the outside of the wheel holding the rim on OR at the center of the wheel holding it to the hub?
4 lug demountable rims are usual Ford style, 5 lug are typical aftermarket, Firestone, and others. This 6 lug is an Atlas all steel spoke wheel, rather unusual, and 6 lug wood spoke wheels would be rare too.
